Peak Intensity Variances With Speed
The variance when measuring peak intensity (mW/cm2) lies in the sample rate of the radiometer versus the time spent under the focal point of the lamp (speed).
A focused UV lamp, has a 3/4 inch focal plane. The UV Power Puck® samples at 25 samples per second. Using the sample rate of the Power Puck, we find that at the 10m/min speed, it is able to accumulate 3.85 samples each inch, but only 2.88 samples which are under the focal plane.
For example:
| 10m/min |
= 390 inches/minute
= 6.5 inches/second
|
|
25 samples/sec |
= 25 samples/6.5 inches
= 3.85 samples/inch
|
|
.75 inch in the focal plane
|
= 2.88 samples under the focal plane (3.85 X .75)
|
Using the above math, here is what happens at 20m/min:
|
20m/min
|
= 780 inches/minutes
= 13 inches/second
|
Now:
25 samples/second (capability of UV Power Puck) = 25 samples/13 inches
Or:
|
but
|
= 1.92 samples per inch
= only 1.44 samples under the focus (1.92 X .75)
|
At some other speeds, here are the results:
- 30m/min = .96 samples under the focus
- 40m/min = .72 samples under the focus
- 50m/min = .58 samples under the focus
- 60m/min = .48 samples under the focus
- 70m/min = .41 samples under the focus
So you can see any speed over 20m/min has less than 1 chance in 25 of sampling under the focus of the lamp.
**Note -- To match a UVIMAP more closely with UV Power Puck or UVICURE Plus, set the UVIMAP sampling rate at 20 samples/sec.
